A
During an investigation, two balloons are attracted to one another. What are the charges on the balloons?
a they are both positive
b they are both negative
c they are both uncharged
d one is positive, and one is negative
d one is positive, and one is negative
A material that allows an electric current to flow through it is an electrical conductor. A material through which an electric current cannot flow easily is called an insulator. Which statement best describes the difference between an insulator and a conductor?
a an insulator has a static charge, and a conductor does not
b a conductor contains more electrons than an insulator
c a conductor is a metal, and an insulator is any material that is not a metal
d an insulator does not have electrons that are free to move, and a conductor does
d an insulator does not have electrons that are free to move, and a conductor does
Which energy transformation occurs when an electrical fan is turned on?
a heat energy into motion energy
b electrical energy into thermal energy
c energy of motion into sound energy
d electrical energy into energy of motion
d electrical energy into energy of motion
Which type of energy does a book have because it is on a shelf?
a chemical
b electrical
c kinetic
d potential
d potential
What form of energy cooks food in a solar cooker?
a chemical energy
b electrical energy
c thermal energy
d mechanical energy
c thermal energy
In a three-pronged plug, one flat prong carries current from the supply that enters the electrical outlet, and the other returns the current to the service panel of the building. The round prong helps protect people from electrical shocks. What has a purpose similar to that of the round prong?
a a magnet
b a generator
c a lightning rod
d an electrical outlet
c a lightning rod
You use energy transformations every day. Which of these is a way that you would use the transformation of electrical energy into motion energy?
a watching your favorite show on television
b taking an elevator to the top of a tall building
c listening to your MP3 player while you walk to school
d turning on the lamp on your desk so you can see to do your homework
b taking an elevator to the top of a tall building
Electric companies send electric power through an electric power grid to your home. At which point is electrical energy produced from other forms of energy?
a substation
b distribution line
c transmission lines
generating station
generating station
Some people hang their laundry to dry outside using an alternative source of energy. On which kind of day will the laundry dry fastest?
a a cold, rainy day
b a cold, cloudy day
c a warm, sunny day
d a warm, cloudy day
c a warm, sunny day
Why do two socks sometimes stick together in a dryer?
a both socks have a positive charge
b both socks have a negative charge
c protons move from one sock to another
d electrons move from one sock to another
d electrons move from one sock to another
Darrell made toast for breakfast by putting a slice of bread into the toaster and turning the toaster on. Which energy transformation did he use to make a piece of toast?
a heat energy into electrical energy
b electrical energy into heat energy
c light energy into electrical energy
d electrical energy into light energy
b electrical energy into heat energy
Suppose someone causes a book to fall from a shelf to the ground. Compared to the total sum of kinetic and potential energy the book has while on the shelf, about how much would it have when it is halfway from the shelf to the ground?
a no energy
b half as much
c twice as much
d the same amount
d the same amount
An electron is the particle most easily removed from an atom. What is the electric charge of a neutral atom from which an electron has been removed?
a negative
b neutral
c nucleus
d positive
d positive
An electric clock in a classroom will not keep time if it is not plugged into an electrical outlet. What does the clock get from the electric current from the outlet?
a batteries
b chemicals
c energy
d time of day
c energy
Objects can lose energy. Which answer describes an example of the mechanical energy of a material decreasing?
a eggs cooking in a pan
b water freezing into ice
c snow melting in the spring
d a ball bouncing on the floor
d a ball bouncing on the floor
If you push down a spring and then release it, it will pop up through the air. Which types of energy does the spring have as it flies through the air?
a electrical and thermal
b kinetic and potential
c potential and electrical
d thermal and kinetic
b kinetic and potential